The fabrication of foam containers with compartmental cutouts is well known. Methods using machinery that have movable working benches to position and move the foam along a cutting blade that may be positioned on a vertical or horizontal axis in relation to the table have been widely used and are described in U.S. Pat. Nos. 6,386,083, 6,125,733 and 6,832,538. Each of the apparatus described present limitations in positioning the foam in relation to the cutting blade. Notably, these conventional cutting apparatus are limited by the type and size of the cutting blade and do not allow internal transverse cuts into the foam to create three dimensional compartments. Other methods as described in U.S. Pat. No. 5,688,538 and in U.S. Pat. No. 6,477,931 use sets of rollers with patterned dies that are pressed against a foam sheet with sufficient force to extrude portions from the foam. The extruded portions are then removed and patterned indentations are formed in the foam sheet. The use of die cut presses at high temperatures as shown in U.S. Pat. No. 7,076,857 stamp patterns into foam sheets to form indentations. Rollers or die cutters have the limitation of high costs to create the molds for each unique pattern indentation thus limiting the ability to create custom designed compartments that would fit oddly shaped objects.
Another method as described in U.S. Pat. No. 5,992,633 pulls electrically heated wires through blocks of foam to form loose fill packaging material to provide for no disassembly of the block foam until the fill material is needed. This method also presents the limitation of positioning the foam along the electrically heated wires and allows for only straight cuts through the foam not transverse cuts to form indentations and compartments. A number of limitations of creating indentations in foam are overcome in U.S. Pat. No. 6,868,765 that uses pulleys and drive arms to position a cutting element carrier to allow rotational movement of a cutting element using a blade knife or cutting wire to cut various shapes and contours within a foam material.
In order to address the limitations of positioning the foam piece to the cutting apparatus and to provide for custom three dimensional compartment designs the present invention uses a laser material processing system to create cuts and indentions within high density foams. A laser material processing system includes a laser source, a power supply, a CPU for receiving a computer program to control beam positioning and corresponding laser modulation, a control panel and a beam delivery system. Patterns are cut from materials using a vector motion of the laser beam by moving a beam delivery system simultaneously along X and Y axes in accordance with the path of the desired pattern while applying a controlled amount of laser energy to cut into or through the material.
As is known in the prior art, the output laser beam is directed along paths parallel to the Y-axis and the X-axis respectively using mirrors and/or other known optical elements. A final mirror and a final focusing lens are located in the beam focusing assembly of the system, such that the final mirror directs the beam out of the plane of the X-Y motion system to the final focusing lens. The final focusing lens then focuses the resulting beam to a focus spot on the subject material workpiece in order to engrave along the surface or cut into the material. Adjustments to the position of the mirror or choosing different types of lens or other optical elements will adjust the focal point of the laser and spot size thus adjust the power output of the laser. These adjustments allow the use of a laser system to cut and engrave plastic, wood, rubber, and rubber-like material, and paper. What has not been accomplished in the prior art is a method of successfully cutting high density foam using a laser material processing system. High density foam is a petroleum based product and particularly flammable. When used with high energy lasers the material is highly susceptible to overheating and catching fire. Any smoke and debris from such overheating or fire will damage the laser system as well as at the very least coat the lens and mirrors of the focusing assembly system causing cracking and destruction of these elements.